linux-stable.git/include/linux/workqueue.h, branch v6.12.97

workqueue: Add new WQ_PERCPU flag

2026-07-24T14:11:09+00:00

[ Upstream commit 930c2ea566aff59e962c50b2421d5fcc3b98b8be ]

Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistentcy cannot be addressed without refactoring the API.

This patch adds a new WQ_PERCPU flag to explicitly request the use of
the per-CPU behavior. Both flags coexist for one release cycle to allow
callers to transition their calls.

Once migration is complete, WQ_UNBOUND can be removed and unbound will
become the implicit default.

tj: Merged doc patch.

Suggested-by: Tejun Heo 
Signed-off-by: Marco Crivellari 
Signed-off-by: Tejun Heo 
Stable-dep-of: 527756cb9ebb ("i3c: master: Make hot-join workqueue freezable to block hot-join during suspend")
Signed-off-by: Sasha Levin

workqueue: Add system_percpu_wq and system_dfl_wq

2026-03-13T16:20:26+00:00

[ Upstream commit 128ea9f6ccfb6960293ae4212f4f97165e42222d ]

Currently, if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.

This lack of consistentcy cannot be addressed without refactoring the API.

system_wq is a per-CPU worqueue, yet nothing in its name tells about that
CPU affinity constraint, which is very often not required by users. Make it
clear by adding a system_percpu_wq.

system_unbound_wq should be the default workqueue so as not to enforce
locality constraints for random work whenever it's not required.

Adding system_dfl_wq to encourage its use when unbound work should be used.

Suggested-by: Tejun Heo 
Signed-off-by: Marco Crivellari 
Signed-off-by: Tejun Heo 
Stable-dep-of: 870c2e7cd881 ("Input: synaptics_i2c - guard polling restart in resume")
Signed-off-by: Sasha Levin

workqueue: Fix another htmldocs build warning

2024-08-21T16:37:39+00:00

Fix htmldocs build warning introduced by 9b59a85a84dc ("workqueue: Don't
call va_start / va_end twice").

Signed-off-by: Tejun Heo 
Reported-by: Stephen Rothwell 
Cc: Matthew Brost

workqueue: Don't call va_start / va_end twice

2024-08-20T19:38:39+00:00

Calling va_start / va_end multiple times is undefined and causes
problems with certain compiler / platforms.

Change alloc_ordered_workqueue_lockdep_map to a macro and updated
__alloc_workqueue to take a va_list argument.

Cc: Sergey Senozhatsky 
Cc: Tejun Heo 
Cc: Lai Jiangshan 
Signed-off-by: Matthew Brost 
Signed-off-by: Tejun Heo

workqueue: Fix htmldocs build warning

2024-08-19T22:18:23+00:00

Fix htmldocs build warning introduced by ec0a7d44b358 ("workqueue: Add
interface for user-defined workqueue lockdep map").

Signed-off-by: Tejun Heo 
Reported-by: Stephen Rothwell 
Cc: Matthew Brost

workqueue: Add interface for user-defined workqueue lockdep map

2024-08-13T19:05:51+00:00

Add an interface for a user-defined workqueue lockdep map, which is
helpful when multiple workqueues are created for the same purpose. This
also helps avoid leaking lockdep maps on each workqueue creation.

v2:
 - Add alloc_workqueue_lockdep_map (Tejun)
v3:
 - Drop __WQ_USER_OWNED_LOCKDEP (Tejun)
 - static inline alloc_ordered_workqueue_lockdep_map (Tejun)

Cc: Tejun Heo 
Cc: Lai Jiangshan 
Signed-off-by: Matthew Brost 
Signed-off-by: Tejun Heo

Merge tag 'mm-nonmm-stable-2024-07-21-15-07' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-07-22T00:56:22+00:00

Pull non-MM updates from Andrew Morton:

 - In the series "treewide: Refactor heap related implementation",
   Kuan-Wei Chiu has significantly reworked the min_heap library code
   and has taught bcachefs to use the new more generic implementation.

 - Yury Norov's series "Cleanup cpumask.h inclusion in core headers"
   reworks the cpumask and nodemask headers to make things generally
   more rational.

 - Kuan-Wei Chiu has sent along some maintenance work against our
   sorting library code in the series "lib/sort: Optimizations and
   cleanups".

 - More library maintainance work from Christophe Jaillet in the series
   "Remove usage of the deprecated ida_simple_xx() API".

 - Ryusuke Konishi continues with the nilfs2 fixes and clanups in the
   series "nilfs2: eliminate the call to inode_attach_wb()".

 - Kuan-Ying Lee has some fixes to the gdb scripts in the series "Fix
   GDB command error".

 - Plus the usual shower of singleton patches all over the place. Please
   see the relevant changelogs for details.

* tag 'mm-nonmm-stable-2024-07-21-15-07' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (98 commits)
  ia64: scrub ia64 from poison.h
  watchdog/perf: properly initialize the turbo mode timestamp and rearm counter
  tsacct: replace strncpy() with strscpy()
  lib/bch.c: use swap() to improve code
  test_bpf: convert comma to semicolon
  init/modpost: conditionally check section mismatch to __meminit*
  init: remove unused __MEMINIT* macros
  nilfs2: Constify struct kobj_type
  nilfs2: avoid undefined behavior in nilfs_cnt32_ge macro
  math: rational: add missing MODULE_DESCRIPTION() macro
  lib/zlib: add missing MODULE_DESCRIPTION() macro
  fs: ufs: add MODULE_DESCRIPTION()
  lib/rbtree.c: fix the example typo
  ocfs2: add bounds checking to ocfs2_check_dir_entry()
  fs: add kernel-doc comments to ocfs2_prepare_orphan_dir()
  coredump: simplify zap_process()
  selftests/fpu: add missing MODULE_DESCRIPTION() macro
  compiler.h: simplify data_race() macro
  build-id: require program headers to be right after ELF header
  resource: add missing MODULE_DESCRIPTION()
  ...

cpumask: make core headers including cpumask_types.h where possible

2024-06-25T05:25:02+00:00

Now that cpumask types are split out to a separate smaller header, many
frequently included core headers may switch to using it.

Link: https://lkml.kernel.org/r/20240528005648.182376-7-yury.norov@gmail.com
Signed-off-by: Yury Norov 
Cc: Amit Daniel Kachhap 
Cc: Anna-Maria Behnsen 
Cc: Christoph Lameter 
Cc: Daniel Lezcano 
Cc: Dennis Zhou 
Cc: Frederic Weisbecker 
Cc: Johannes Weiner 
Cc: Juri Lelli 
Cc: Kees Cook 
Cc: Mathieu Desnoyers 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Rafael J. Wysocki 
Cc: Rasmus Villemoes 
Cc: Tejun Heo 
Cc: Thomas Gleixner 
Cc: Ulf Hansson 
Cc: Vincent Guittot 
Cc: Viresh Kumar 
Cc: Yury Norov 
Signed-off-by: Andrew Morton

workqueue: Increase worker desc's length to 32

2024-06-07T16:24:16+00:00

Commit 31c89007285d ("workqueue.c: Increase workqueue name length")
increased WQ_NAME_LEN from 24 to 32, but forget to increase
WORKER_DESC_LEN, which would cause truncation when setting kworker's
desc from workqueue_struct's name, process_one_work() for example.

Fixes: 31c89007285d ("workqueue.c: Increase workqueue name length")

Signed-off-by: Wenchao Hao 
CC: Audra Mitchell 
Signed-off-by: Tejun Heo

workqueue: Use "@..." in function comment to describe variable length argument

2024-04-22T20:08:04+00:00

Previously, it was using "remaining args" without leading "@" which isn't
valid. Let's follow snprintf()'s example and use "@...".

Signed-off-by: Tejun Heo 
Reported-by: Stephen Rothwell